fix test suite

mysql-test/r/kill.result

@@ -60,9 +60,7 @@ SET DEBUG_SYNC= 'now WAIT_FOR in_sync';
 KILL @id;
 SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
 Got one of the listed errors
-SELECT 1;
-1
-1
+Got one of the listed errors
 SET DEBUG_SYNC = 'RESET';
 DROP TABLE t1, t2;
 SET DEBUG_SYNC= 'before_acos_function SIGNAL in_sync WAIT_FOR kill';

mysql-test/t/flush_read_lock_kill.test

@@ -65,7 +65,7 @@ KILL CONNECTION @id;
 connection con1;
 --echo # Try to reap FLUSH TABLES WITH READ LOCK, 
 --echo # it fail due to killed statement and connection.
---error 1317,2013
+--error 1317,2013,1927
 reap;
 
 --echo # Switching to 'con2'.

mysql-test/t/kill.test

@@ -142,9 +142,12 @@ KILL @id;
 SET DEBUG_SYNC= 'now WAIT_FOR con1_end';
 
 connection con1;
---error 1317,1053,2006,2013
+--error 1317,1053,2006,2013,1927
 reap;
+--disable_query_log
+--error 2013,0
 SELECT 1;
+--enable_query_log
 
 connection default;
 SET DEBUG_SYNC = 'RESET';

sql/threadpool_common.cc

@@ -71,7 +71,9 @@ static inline bool thread_attach(THD* thd, char *stack_start, PSI_thread **save_
 static inline void thread_detach(THD* thd, PSI_thread *restore_psi_thread)
 {
   DBUG_ENTER("thread_detach");
+  mysql_mutex_lock(&thd->LOCK_thd_data);
   thd->mysys_var = NULL;
+  mysql_mutex_unlock(&thd->LOCK_thd_data);
 #ifndef DBUG_OFF
   /*
     If during the session @@session.dbug was assigned, the
@@ -161,7 +163,7 @@ int threadpool_process_request(THD *thd)
   PSI_thread *psi_thread;
   thread_attach(thd, (char *)&thd, &psi_thread);
 
-  if (thd->killed == KILL_CONNECTION)
+  if (thd->killed >= KILL_CONNECTION)
   {
     /* 
       kill flag can be set have been killed by